This invention relates to methods of fabricating radio frequency remote intelligent communications devices. The invention has applicability to methods of processing liquids, epoxy fabrication methods and processes involving a mixture of different liquids.
Electronic identification systems typically comprise two devices which are configured to communicate with one another. Preferred configurations of the electronic identification systems are operable to provide such communications via a wireless medium.
One such configuration is described in U.S. patent application Ser. No. 08/705,043, filed Aug. 29, 1996, assigned to the assignee of the present application and incorporated herein by reference. This application discloses the use of a radio frequency (RF) communication system including communication devices. The communication devices include an interrogator and a transponder such as a tag or card.
The communication system can be used in various identification and other applications. The interrogator is configured to output a polling signal which may comprise a radio frequency signal including a predefined code. The transponders of such a communication system are operable to transmit an identification signal responsive to receiving an appropriate command or polling signal. More specifically, the appropriate transponders are configured to recognize the predefined code. The transponders receiving the code subsequently output a particular identification signal which is associated with the transmitting transponder. Following transmission of the polling signal, the interrogator is configured to receive the identification signals enabling detection of the presence of corresponding transponders.
Such communication systems are useable in identification applications such as inventory or other object monitoring. For example, a remote identification device is attached to an object of interest. Responsive to receiving the appropriate polling signal, the identification device is equipped to output an identification signal. Generating the identification signal identifies the presence or location of the identification device and article or object attached thereto.
In but one aspect, the invention comprises a method of fabricating a radio frequency intelligent communications device. A substrate is formed to have conductive lines, at least a portion of which comprise an antenna. An integrated circuit chip and a battery are conductively bonded to the conductive lines on the substrate. A visible spectrum colored liquid resin and a visible spectrum substantially colorless liquid hardener are combined into an epoxy mixture. The liquid hardener has a fluorescent material received therein. Radiation is impinged onto the epoxy mixture effective to cause the fluorescent material to fluoresce. From the fluorescing fluorescent material, degree of homogeneity in the epoxy mixture can be determined. Upon achieving desired homogeneity, the substrate with chip and battery are encapsulated in the epoxy mixture, with the epoxy mixture being cured.
The invention also has applicability to epoxy systems and other liquid mixtures having at least two liquid components. The invention also comprises providing first and second liquids where one of said liquids has an invisible component therein. The first and second liquids are combined together into a mixture. The invisible component remains invisible in the mixture upon the combining. After the combining, the component is rendered visible, for example by exposure to ultraviolet radiation. Degree of homogeneity in the mixture is determined while the component has been rendered visible. After the determining, the component is rendered invisible, for example by removing the ultraviolet light source.